eigenvals {vegan} | R Documentation |
Function extracts eigenvalues from an object that has them. Many multivariate methods return such objects.
eigenvals(x, ...) ## S3 method for class 'cca': eigenvals(x, constrained = FALSE, ...) ## S3 method for class 'eigenvals': summary(object, ...)
x |
An object from which to extract eigenvalues. |
object |
An eigenvals result object.
|
constrained |
Return only constrained eigenvalues. |
... |
Other arguments to the functions (usually ignored) |
This is a generic function that has methods for cca
,
wcmdscale
, prcomp
and
princomp
result objects. The default method also
extracts eigenvalues if the result looks like being from
eigen
or svd
. Functions
prcomp
and princomp
contain square roots
of eigenvalues that all called standard deviations, but
eigenvals
function returns their squares. Function
svd
contains singular values, but function
eigenvals
returns their squares. For constrained ordination
methods cca
, rda
and
capscale
the function returns the both constrained and
unconstrained eigenvalues concatenated in one vector, but the partial
component will be ignored. However, with argument
constrained = TRUE
only constrained eigenvalues are returned.
The summary
of eigenvals
result returns eigenvalues,
proportion explained and cumulative proportion explained.
An object of class "eigenvals"
which is a vector of eigenvalues.
Jari Oksanen.
eigen
, svd
, prcomp
,
princomp
, cca
, rda
,
capscale
, wcmdscale
,
cca.object
.
data(varespec) data(varechem) mod <- cca(varespec ~ Al + P + K, varechem) ev <- eigenvals(mod) ev summary(ev)